Impulse AQ Switch From Lithium Ion To Nickel Metal Hydride Batteries

[Steve Herschbach 31,448]

The Impulse AQ was said to have Li-Ion batteries up until recently, and is now said to be coming with a NiMH battery pack. I am guessing this is related to increasing issues surrounding the shipping and transport of Lithium Ion batteries. Especially large external batteries. See this thread.

 

[pjrough 84]

It is a pity and a big problem for everybody:

- manufacturer will have to sell a detector packed with NiMN at quite high price tag

- the buyer will get detector limited in terms of performance.

- serious detectorists will have to modify quite expensive unit to get desired performance.

What would be a stock battery configuration? I am wrong thinking that it was planned to be 16v machine?

Stock battery compartment doesn't seems to be able to fit inside 12s2p configuration? if it will be 1p battery configuration, the hunting time might be limited to 3 - 3.5h 😞

... apart PI machine tend to be quite power demanding and it will be limited if stock NiMH can't deliver necessary current..

[ALEXANDRE TARTAR 733]

It is not the voltage that is important in a PI but the current in the coil and the number of turns.
Of course with a similar coil (fixed resistance), a higher voltage gives a higher current (U = R * I)
It is better a PI 6 volts and 4 amperes in the coil rather than a PI 16v and 1A in the coil ...

At startup we designed the battery pack on the basis of li-ion. But it should have cost between 50K and 100K USD of compliance. Since we wanted to change the mechanical type of battery in the future to something more universal, we haven't chosen the li-ion option for the now.

[pjrough 84]

Alexandre, I got your point about the compliance fee.

Am I right thinking that 16v 1A in the coil might be close to the true?

I think so, knowing that TDI withdraws around 0.7A at 16v and your machine is planned to be more powerful...

1a current is not something terrible for quality brand NiMHs, and understanding you might be fitting 2p battery to reach 4h+of hunting time (2000 mAh typical capacity of quality brand NiMH).

in any case, thanks for posting here, and nice to know that your product is reaching the point of official launch.

 

[Steve Herschbach 31,448]

I am not sure if you can answer this yet Alexandre but I will ask. Is the Impulse AQ voltage regulated?

[ALEXANDRE TARTAR 733]

Yes the voltage is regulated at 15V and therefore also the current until the end of the battery.

Do not confuse the current in the coil and the consumption of the detector on the battery in mAh

Here we are talking about a battery consumption in all metal mode of 520mAh for> 4,000 PPS and a coil current of 2.5A at peak.

In volcanic mode 1600 PPS and 360 mAh for the battery consuption in the coil of 2.5A at peak.

If I am not mistaken, the current in the coil of the TDI is only 1.8A.
If it consumes more on the battery for a lower coil current it is because it loses all its power in Joule effect (in the dissipation of heat through the components)

 

[Steve Herschbach 31,448]

The reason I ask is some PI detectors like the TDI are not regulated and so people try and get more depth by applying more power.... at the risk of electronic failure of course.

I like that using an external power pack makes battery alternatives very easy. I am sure there will be a larger battery option, perhaps belt mounted, for those who want longer operating times between charges. And of course Li-Ion as an option.  Interesting to hear that other battery configurations are possibly planned in the future. No doubt to be used in conjunction with other future models still under development.

[ALEXANDRE TARTAR 733]

10 minutes ago, Steve Herschbach said:

The reason I ask is some PI detectors like the TDI are not regulated and so people try and get more depth by applying more power.... at the risk of electronic failure of course.

Yes it is true, and in general the capacitors does not hold the shock because they have for several detectors voltages of 16V.
Raising the voltage causes the current to rise slightly and causes the flyback to rise, and since the mosfets are not designed for this, they go off in an avalanche and are very hot or burn. In addition it lengthens the damping and requires a longer pulse delay.

The improvement is not very complicated on these detectors but requires good fundamental knowledge.

[bklein 21]

Curious if you have tried supercapacitors in the TX circuit...

[Joe Beechnut OBN 2,186]

Very easy to build our own LiPo 14.4v  with a excalibur battery pod. Once we get our hands on a battery pack. I did read that the M-8 connector for the headphones had went to a 5 pin. Bottom picture is of m-12 endcaps I made for the xcaliburs...